1. Field of the Invention
The invention relates generally to the field of photographic cameras. More particularly, the invention relates to a camera in which there is provided an improved mechanism for reminding the photographer to set a film speed (sensitivity) setting member to a position representative of the speed of unexposed film in the camera before taking the first picture.
2. Description of the Prior Art
It is well known in the art relating to photographic cameras to provide a camera with a manually operated film speed setting member. Typically, the setting member is movable to a plurality of film speed related positions, e.g., ISO 100, 200, 400 and 1000, corresponding to the various speed films with which the camera is intended to be used. When the photographer moves the setting member to a selected position, an adjustment is made to the exposure control means in the camera which is used in the determination of the correct exposure of the film during picture-taking. One of the problems that is encountered, however, is that the photographer does not always remember to move the setting member to the correct position after he or she has loaded unexposed film in the camera. As a result, the film will be underexposed or overexposed during picture-taking.
Prior art devices for reminding a photographer to move a film speed setting member to a position representative of the speed of unexposed film in the camera are disclosed in Japan applications (Kokai) No. 59-121030 and 59-121031, opened for public inspection on July 12, 1984. In the first Japan application, a locking pin is spring urged outwardy at the rear of the camera in response to the opening of a back door of the camera. The locking pin during movement to its extended position pivots a release lever which releases a manually operated film speed setting slide for spring urged movement to engage the locking pin. When engaged in its extended position, the locking pin prevents the back door from being closed. This serves as a reminder to the photographer, after unexposed film is loaded in the camera, to move the film speed setting slide to a position representative of the speed of the loaded film. In the film speed related position, the film speed setting slide is disengaged from the locking pin, permitting the locking pin to be moved inwardly to allow the back door to be closed. The other Japan application is similar to the first one except that a shutter release button is prevented by the film speed setting slide from being depressed until the slide is reset to a film speed related position.
Preventing the back door from being closed or preventing the shutter release button from being depressed as in the two Japan applications, in order to remind the photographer to move a film speed setting member to a position representative of the speed of unexposed film in the camera, is not without certain problems. For example, in the first application, the photographer may accidentally deform the back door in the vicinity of the locking pin should he or she attempt to close the door without first resetting the film speed setting slide to the position corresponding to the speed of the loaded film. Alternatively, in the other Japan application, the opportunity to take a picture may be lost because the shutter release button cannot be depressed until the photographer resets the film speed setting slide.